In Prometheus, we saw that the last Engineer on LV-223 slept for 2000 years until humans came. Why did he sleep for 2000 years? Why didn't he go to "Paradise" immediately?
My impression from the movie was that he'd entered the pod in some haste, and probably had set it to sleep indefinitely, in the hopes that someone else would wake him once the outbreak was dealt with.
He was correct in this hope, though not in the way that he'd expected.
My understanding was that the Engineer was either already in stasis prior to his crew-mates being infected and was set to be woken up when the ship reached Earth, or alternatively, placed himself in stasis to avoid infection. I prefer the former explanation as, upon waking up, he does not really show any interest in the bio-weapon's present status.